1. Field
This disclosure relates generally to an intra-medullary guide wire and more particularly to a lateral light-emitting device capable of connecting an intra-medullary guide wire.
2. Description of Related Art
Lower extremities fractures are treated by intra-medullary nailing that is a golden standard method for the recent twenty years. The insertion of the nail requires a guide wire to guide the insertion of the intra-medullary nail into the medullary cavity.
Interlocking nail provides good fixation thus better treatment efficacy over the conventional medullary nails. During operation, it must be localized the distal and proximal screw holes and then use screws to fix the nail (locking the nail). Because the nail is embedded in the medullary cavity, so a standard approach is to use the roentgenography to “see” the screw holes and completed this procedure.
Please reference to U.S. Pat. No. 5,417,688. The optical distal targeting system and method for an intra-medullary nail for detecting the location of transverse holes of an intra-medullary nail which has been inserted into a long bone and for aligning a surgical drill to the transverse holes is disclosed. An insert having a light source at its distal end emitting non-ionizing electromagnetic radiation in the visible spectrum or infrared is inserted into the intra-medullary nail, such that the light source is placed adjacent to the transverse holes. The light source may be a directional radiation output emitting the radiation in a direction perpendicular to the axis of the intra-medullary nail. The light source may alternatively be an isotropic radiation output emitting radiation in all directions. The surgeon detects the transmitted radiation on the surface of the body of the patient and aligns the drill with the emitted radiation.
Please also reference to TW issued U.S. Pat. No. 485,036. A medullary guide wire with a self-attached lighting device is disclosed. The front end of the guide wire is self-attached with a lighting device, and the visible light or near infrared light from the lighting device will penetrate out of the tissues and bone surface and is used for detecting the screw hole. During screw hole detection, the light-emitting medullary guide wire is stayed in the nail inserted into the marrow cavity and the light emitted through the screw hole and the bone surface is observed from outside of the body. The light-emitting guide wire enables a quick and convenient way to position the screw holes while performing the intra-medullary nailing procedure.
The two structures of the above mentioned prior arts are used by illuminating from within the body to proceed the operation so as to reduce the risk of additional traumas and improve the efficacy of operations, but because the light source is arranged at the front end of the guide wire so a significant portion of the emitted light will travel axially and is not useful for detecting the screw hole which lies on the lateral side of the nail. It may thus require to increase the light power that caused higher power consumption or even injuries resulting from high temperature generated from the high light intensity.
The structure disclosed in a U.S. Pat. No. 5,417,688 has a hole dug laterally so as to divert the light to emit through lateral sides. However, because the light source is disposed in an open structure, the lighting device is easily permeated by the body fluids to cause the device malfunction or contaminate the surrounding tissues.
In addition, the lighting device and the medullary guide wire are fixed in one piece, this increases the manufacturing difficulty as the diameter of the guide wire is only about 3 mm. Furthermore, because the lighting device is arranged at the front end of the medullary guide wire, the medullary guide wire needs to be inserted into the marrow cavity, and the light source has no protecting device to protect it while proceeding the operation, it is easily to damage the light source in the marrow cavity resulting from colliding bone tissue. When this happened, the assembly of the lighting device and the medullary guide wire must be discarded all together. It will be a waste of resources.